U.S. patent application number 10/249832 was filed with the patent office on 2004-11-18 for face mask with double breathing chambers.
Invention is credited to Peng, Zheng, Xu, Zhaoxia.
Application Number | 20040226563 10/249832 |
Document ID | / |
Family ID | 33415572 |
Filed Date | 2004-11-18 |
United States Patent
Application |
20040226563 |
Kind Code |
A1 |
Xu, Zhaoxia ; et
al. |
November 18, 2004 |
Face Mask with Double Breathing Chambers
Abstract
A face mask (100) with double breathing chambers. Face mask
(100) includes an outer face piece (102) for covering the nose,
mouth and eyes of a wearer, an inner face piece (104) for covering
the nose and mouth of the wearer, a separation piece (06, made of a
substantially impermeable material, substantially dividing face
piece (04) into a nose portion (104a) and a mouth portion (104b),
thereby forming a nose chamber and a mouth chamber, such that gas
communication between the two chambers is minimized, an exhalation
device (108) for allowing air to pass therethrough from an interior
gas space to an exterior gas space, an inhalation device (110) for
allowing air to pass therethrough from an exterior gas space to an
interior gas space, and a lens (112) for allowing the wearer to
watch therethrough. In another embodiment of the present invention,
face mask (200) includes a face piece (202), made of a filtration
material, a separation member (204), made of a substantially
impermeable material, substantially dividing face piece (202) into
a nose portion (202a) and a mouth portion (202b), thereby forming a
nose chamber and a mouth chamber, such that gas communication
between the two chambers is minimized. The face mask of the present
invention is more comfortable and hygienic to wear compared with
prior art products. This invention has utility with many types of
face masks, including medical, clean-room, firefighting,
chemical-biological applications, etc.
Inventors: |
Xu, Zhaoxia; (Ypsilanti,
MI) ; Peng, Zheng; (Ypsilanti, MI) |
Correspondence
Address: |
ZHAOXIA XU
4694 SYCAMORE DR.
YPSILANTI
MI
48197
US
|
Family ID: |
33415572 |
Appl. No.: |
10/249832 |
Filed: |
May 12, 2003 |
Current U.S.
Class: |
128/206.21 ;
128/206.23 |
Current CPC
Class: |
A62B 18/02 20130101 |
Class at
Publication: |
128/206.21 ;
128/206.23 |
International
Class: |
A62B 018/08; A62B
018/02 |
Claims
1. A face mask for a wearer, said face mask comprising: an outer
face piece covering at least the nose, mouth, and eyes of said
wearer; an inner face piece covering the nose and mouth of said
wearer installed inside said outer face piece; a separation piece
substantially dividing said inner face piece into a nose portion
and a mouth portion, thereby, forming a nose chamber and a mouth
chamber, and having a first end attached to said inner face piece
and a second end extending rearward toward the facial area of said
wearer in between the nose and mouth; an exhalation device
installed on said outer face piece for allowing exhaled air to pass
therethrough from an interior gas space to an exterior gas space;
an inhalation device installed on said outer face piece for
allowing air to pass therethrough from an exterior gas space to an
interior gas space; and lens means connected to said outer face
piece.
2. A face mask as defined in claim 1, wherein said separation piece
is made of a substantially impermeable material.
3. A face mask as defined in claim 1, wherein said exhalation
device includes a one-way valve for allowing exhaled air to pass
therethrough from an interior gas space to an exterior gas
space.
4. A face mask as defined in claim 1, wherein said exhalation
device includes filter means for filtering the air passing
therethrough.
5. A face mask as defined in claim 1, wherein said inhalation
device includes filter means for filtering the air passing
therethrough.
6. A face mask as defined in claim 5, wherein said inhalation
device includes a one-way valve for preventing exhaled air from
passing therethrough.
7. A face mask for a wearer, said face mask comprising: a face
piece covering at least the nose and mouth of said wearer; and a
separation member substantially dividing said face piece into a
nose portion and a mouth portion, thereby forming a nose chamber
and a mouth chamber, and having a first end attached to said face
piece and a second end extending rearward toward the facial area of
said wearer in between the nose and mouth.
8. A face mask as defined in claim 7, wherein said separation
member is made of a substantially impermeable material.
9. A face mask as defined in claim 8, said face mask further
including: an exhalation device installed on said face piece for
allowing exhaled air to pass therethrough from an interior gas
space to an exterior gas space; and an inhalation device installed
on said face piece for allowing air to pass therethrough from an
exterior gas space to an interior gas space.
10. A face mask as defined in claim 9, wherein said exhalation
device includes a one-way valve for allowing exhaled air to pass
therethrough from an interior gas space to an exterior gas
space.
11. A face mask as defined in claim 9, wherein said exhalation
device includes filter means for filtering the air passing
therethrough.
12. A face mask as defined in claim 9, wherein said inhalation
device includes filter means for filtering the air passing
therethrough.
13. A face mask as defined in claim 12, wherein said inhalation
device includes a one-way valve for preventing exhaled air from
passing therethrough.
14. A face mask as defined in claim 8, wherein said face piece is
made of a filtration material.
15. A face mask as defined in claim 14, wherein said face piece is
a molded face piece having a cup-shaped shape-retaining layer.
16. A face mask as defined in claim 15, said face mask further
including an exhalation device installed on said face piece for
allowing exhaled air to pass therethrough from an interior gas
space to an exterior gas space.
17. A face mask as defined in claim 16, wherein said exhalation
device includes a one-way valve for allowing exhaled air to pass
therethrough from an interior gas space to an exterior gas
space.
18. A face mask as defined in claim 16, wherein said exhalation
device includes filter means for filtering the air passing
therethrough.
19. A face mask as defined in claim 14, wherein said face piece is
a flat face piece.
20. A method for using a face mask, said method comprising the
steps of: providing said face mask comprising a face piece for
covering at least the nose and mouth of a wearer, a separation
member, made of a substantially impermeable material, substantially
dividing said face piece into a nose portion and a mouth portion,
thereby forming a nose chamber and a mouth chamber, and having a
first end attached to said face piece and a second end extending
rearward toward the facial area of said wearer in between the nose
and mouth, such that the second end of said separation member is
conformal to the face of said wearer; fastening said face mask onto
the face of said wearer, such that said nose portion is covering
the nose area and said mouth portion is covering the mouth area,
and such that said separation member is disposed in between the
nose and mouth of said wearer; inhaling with the nose; and exhaling
with the mouth; and whereby the exhaled air is directed out of the
interior gas space through said mouth portion, the re-inhalation of
residual exhaled air is totally eliminated, and the fogging of
eyeglasses is minimized.
Description
BACKGROUND OF INVENTION
[0001] This invention generally relates to face masks. More
specifically, this invention relates to face masks with double
breathing chambers.
[0002] Face masks that have been designed to protect the wearer are
commonly referred to as "respirators", whereas masks that have been
designed primarily to protect other persons and things are
generally referred to as "face masks" or simply "masks". In this
invention disclosure, they are generally termed as "face masks" or
simply "masks".
[0003] People wear masks for two common purposes: (1) to prevent
contaminants from entering the wearer's respiratory system; and (2)
to protect others from being exposed to pathogens and other
contaminants exhaled by the wearer.
[0004] It is believed that comfortable masks are much more likely
to be worn and therefore are more beneficial from a safety
standpoint. Safety of the wearer and others is a primary concern in
mask development.
[0005] Some masks are categorized as "disposable", because they are
used for relatively short time periods and discarded thereafter.
These masks are typically, made from non-woven fibrous webs.
However, fibers that protrude from the web have caused discomfort
to its wearer by creating a tickling sensation. Disposable masks
generally fall into two different categories, namely, fold-flat
masks and molded masks. Fold-flat masks are packed flat but are
formed with seams, pleats and/or folds that enable them to be
opened into a cup-shaped configuration. Molded masks, however, are
preformed into a desired face-fitting configuration and generally
retain that configuration during use.
[0006] Molded masks are commonly made from thermally bonding
fibers. Thermally bonding fibers bond to adjacent fibers after
being heated and cooled. These face masks are cup-shaped ones that
have at least one layer of thermally bonding fibers. The layer of
thermally bonding fibers is termed a "shaping layer", and is used
to provide a shape to the mask and support for one or multiple
filtration layers. The shaping layer may reside on an inner portion
of the mask (adjacent to the face of the wearer), or it may reside
on an outer portion or in the middle of multiple filtration
layers.
[0007] In some cases, all of the layers of materials are assembled
together before the shaping layer is molded so that all of the
layers are subjected to the molding procedure. In other cases, only
the material for the shaping layer is molded and the other layers
are applied afterwards.
[0008] Other masks are categorized as "non-disposable", because
they are used repeatedly. After each use they are decontaminated
(cleaned), with/without some part exchanges. These masks are
typically made from multi-layer fabrics, e.g., some surgical masks,
or of semi-rigid and impermeable materials, e.g., full-face and
half-face masks including firefighter masks and chemical-biological
masks. The latter is usually more advanced than most of the
aforementioned ones.
[0009] Intensive research has been directed toward mask development
for various applications. Many patents have been granted.
[0010] U.S. Pat. No. 5,803,075, issued to Yavitz, on Sep. 8, 1998,
describes a flat surgical mask for covering the nose and mouth of a
wearer.
[0011] U.S. Pat. No. 4,384,577, issued to Huber, et al., on May 24,
1983, describes a molded face mask for filtering air.
[0012] U.S. Pat. No. 6,041,782, issued to Angadjivand, et al., on
Mar. 28, 2000, describes a molded respiratory mask comprising a
molded, cup-shaped, shape-retaining shell.
[0013] U.S. Pat. No. 6,460,539, issued to Japuntich, et al., on
Oct. 8, 2002, describes a respirator that includes an integral
filter element, an exhalation valve, and impactor element.
[0014] U.S. Pat. No. 6,116,239, issued to Grove, et al., on Jan.
23, 2001, describes an advanced chemical-biological mask for
protecting a wearer from chemical and biological environmental
contaminants.
[0015] U.S. Pat. No. 4,419,993, issued to Petersen, on Dec. 13,
1983, describes a surgical mask comprising a face piece divided
into an upper region and a lower region. The lower region is more
permeable. The face mask may be suitably worn by eye-glass clad
operation room staff members since exhaled air is directed downward
away from the eyes of the wearer of the mask.
[0016] A big issue associated with wearing a mask is the discomfort
it causes to the wearer. This discomfort is caused by the warm,
humid, high-carbon-dioxide exhaled air resides inside the mask
interior gas space and within filtration materials during
exhalation. The situation gets even worse for people who have to
wear masks for pro-longed periods of time, such as clean-room
workers, operation-room doctors and nurses, patients suffering from
extremely contagious respiratory diseases, like SARS, firefighters
in fighting fire disasters, and soldiers in chemical and biological
battle fields.
[0017] Based on the inventors' investigation/observation, a
person's breathing includes two primary activities, namely,
inhalation and exhalation. There is a brief pause in between.
Inhalation is not causing discomfort to the wearer so long as the
resistance of the filtration material to the air going through the
face mask is small. Through innovative designs, especially proper
selections of filtration materials, discomfort caused by inhalation
has been minimized. The primary discomfort associated with wearing
a face mask comes from exhalation. The warm and humid exhaled air
and the high-carbon-dioxide content in it is the identified root
cause. The exhaled air fills the whole interior gas space during
exhalation and causes discomfort and re-inhalation of the residual
exhaled air.
[0018] It is ideal to purge all the exhaled air out of the face
mask before next inhalation. However, even the most advanced face
masks fails to achieve this target. Research work has been
concentrating on facilitating exhalation by providing valves to
reduce the resistance pressure required for propelling the
exhalation air out of the mask. Most non-medical masks, like
firefighter and chemical-biological masks, fall in this category.
For face masks of medical use, U.S. Pat. No. 6,460,539 discloses a
valved face mask with a filter.
[0019] Unfortunately, residual exhalation air trapped inside the
area enclosed by the mask and the wearer' face remains therein. The
larger the enclosed space therein, the more residual exhaled air.
Re-inhalation of this residual exhaled air is causing discomfort to
the wearer and it is not healthy/hygienic, especially for the
people suffering from extremely contagious respiratory diseases,
such as SARS. These patients are generally required to wear masks
due the extremely contagious nature of the disease.
[0020] However, even the resistance or pressure drop required to
propel the exhalation air has been minimized to a minimal level,
completely purging the exhalation air by the wearer is still out of
the question. This is due to the fact that the exhalation air
trapped inside the enclosed space formed by the face mask and its
wearer' face and within the filtration materials cannot be purged
by the wearer without outside help.
[0021] There are two approaches for tackling the issue of
discomfort and re-inhalation of residual exhaled air associated
with wearing a face mask, 1) directing the exhalation air in a
controlled manner to a smaller and less sensitive area to minimize
the discomfort and to avoid re-inhalation of the residual exhaled
air; or 2) bringing in outside help namely, a device to remove it.
This invention disclosure is taking the former approach.
[0022] Therefore, it remains desirable to provide a face mask,
which can (i) prevent contaminants from passing from the wearer to
the ambient air; (ii) prevent contaminants from passing from the
ambient air to the wearer; (iii) prevent splash-fluids from
entering the mask interior; (iv) allow warm, humid,
high-carbon-dioxide air to be quickly purged from the mask's
interior gas space; and (v) direct the exhalation air in a
controlled manner to a smaller and less sensitive area for
avoiding/minimizing the discomfort to the wearer and the
re-inhalation of the residual air trapped inside the mask interior
gas space and within the filtration materials.
SUMMARY OF INVENTION
[0023] Accordingly, the present invention is a face mask. This face
mask comprises an outer face piece covering the nose, mouth and
eyes of a wearer, a inner face piece covering the nose and mouth, a
separation piece, made of a substantially impermeable material,
substantially dividing the inner face piece into a nose portion and
a mouth portion, thereby, forming a nose chamber and a mouth
chamber, such that the gas communication between the two chambers
is minimized, an exhalation device for allowing exhalation air to
pass from an interior gas space to an exterior gas space during an
exhalation, an inhalation device for allowing air to pass from an
exterior gas space to an interior gas space during inhalation, a
lens for allowing the wearer to watch therethrough, and an
adjustable and/or elastic strap for tightening the face mask
against the wearer's face.
[0024] In another embodiment of this present invention, this face
mask comprises a face piece covering the nose and mouth of a
wearer, a separation piece, made of a substantially impermeable
material, substantially dividing the face piece into a nose portion
and a mouth portion, thereby, forming a nose chamber and a mouth
chamber, such that the gas communication between the two chambers
is minimized, an exhalation device for allowing exhalation air to
pass from an interior gas space to an exterior gas space during an
exhalation, an inhalation device for allowing air to pass from an
exterior gas space to an interior gas space during inhalation, and
an adjustable and/or elastic strap for tightening the face mask
against the wearer's face.
[0025] In an further more embodiment of the present invention, this
face mask comprises a face piece, made of a permeable filtration
material, covering at least the nose and mouth of a wearer, a
separation member, made of a substantially impermeable material,
substantially dividing the face piece into a nose portion and a
mouth portion, thereby, forming a nose chamber and a mouth chamber,
such that the gas communication between the two chambers is
minimized, and an adjustable and/or elastic strap for tightening
the face mask against the wearer's face.
[0026] Accordingly, the followings are some of the objects,
features, and advantages of the present invention:
[0027] It is an object of the present invention to provide a face
mask that prevents contaminants from entering the wearer's
respiratory system.
[0028] It is another object of the present invention to provide a
face mask that protects others from being exposed to pathogens and
other contaminants exhaled by the wearer.
[0029] It is a further more object of the present invention to
provide a face mask that minimizes the discomfort and fogging of
eyeglasses associated with wearing a face mask and avoids the
re-inhalation, by the wearer, of the residual exhaled air trapped
inside the enclosed space and within the filtration materials,
whereby the face mask of the present invention is more comfortable
and hygienic to wear.
[0030] It is a still further more object of the present invention
to provide a face mask that more efficiently utilizes filtration
materials and has longer utility life by having different
filtration materials for inhalation and exhalation,
respectively.
[0031] It is a feature of the present invention that this face mask
has a substantially impermeable separation member substantially
dividing the face piece into a nose portion and a mouth portion,
thereby, forming a nose chamber and a mouth chamber, such that the
gas communication between the two chambers is minimized and such
that exhalation air can be directed to the mouth chamber, whereby
the re-inhalation of residual exhaled air is totally
eliminated.
[0032] It is an advantage of the present invention that this face
mask directs the exhalation air to the mouth portion, thereby
minimizing the area size irritated by the warm and humid exhaled
air.
[0033] It is another advantage of the present invention that this
face mask totally eliminated the possibility of re-inhalation of
residual exhaled air by the wearer, whereby it is comfortable and
hygienic to wear.
[0034] It is a further more advantage of the present invention that
this face mask is beneficial to the people who wears glasses. By
directing exhaled air in a controlled manner and to a specific
area, fogging of glasses is minimized.
[0035] Further more features and advantages of the present
invention will be readily appreciated, as the same becomes better
understood after reading the subsequent description when considered
in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1 illustrates an embodiment of the present invention, a
full-face face mask 100 covering the wearer's nose, mouth, and
eyes.
[0037] FIG. 2 illustrates a cross-sectional view of face mask 100,
taken along line A-A of FIG. 1.
[0038] FIG. 3 illustrates a cross-sectional view of exhalation
device 108, for an alternative design.
[0039] FIG. 4 illustrates a cross-sectional view of inhalation
device 170, taken along line B-B of FIG. 1.
[0040] FIG. 5 illustrates another embodiment of the present
invention, a half-face face mask 150 covering the wearer's nose and
mouth.
[0041] FIG. 6 illustrates a cross-sectional view of face mask 150,
taken along line A-A of FIG. 5.
[0042] FIG. 7 illustrates a cross-sectional view of exhalation
device 156, for an alternative design.
[0043] FIG. 8 illustrates a cross-sectional view of inhalation
device 158, taken along line B-B of FIG. 5.
[0044] FIG. 9 illustrates a further more embodiment of the present
invention, a molded face mask 200 covering the wearer's nose and
mouth.
[0045] FIG. 10 illustrates a cross-sectional view of face mask 200,
taken along line A-A of FIG. 9.
[0046] FIG. 11 illustrates a perspective view of face mask 200,
viewing from the back, indicating a design of separation member
204.
[0047] FIG. 12 illustrates a perspective view of face mask 200,
viewing from the back, indicating an alternative design of
separation member 204.
[0048] FIG. 13 illustrates a cross-sectional view of a design of
separation member 204 joining face piece 202.
[0049] FIG. 14 illustrates a cross-sectional view of an alternative
design of separation member 204 joining face piece 202.
[0050] FIG. 15 illustrates a cross-sectional view of another
alternative design of separation member 204 joining face piece
202.
[0051] FIG. 16 illustrates a cross-sectional view of a further more
alternative design of separation member 204 joining face piece
202.
[0052] FIG. 17 illustrates a front view of an alternative design of
face mask 200 of FIG. 9.
[0053] FIG. 18 illustrates a still further more embodiment of the
present invention, a fold flat face mask 210 covering the wearer's
nose and mouth.
[0054] FIG. 19 illustrates a perspective view of face mask 210 on a
wearer.
[0055] FIG. 20 illustrates a cross-sectional view of face mask 210,
taken along line A-A of FIG. 18, but on a wearer at a working
position.
[0056] FIG. 21 illustrates a perspective view of face mask 210,
viewing from the back, indicating a design of separation member
214.
[0057] FIG. 22 illustrates a perspective view of face mask 210,
viewing from the back, indicating an alternative design of
separation member 214.
DETAILED DESCRIPTION
[0058] This invention has utility with many types of face masks,
including half masks that cover the wearer's nose and mouth; full
face masks that cover the wearer's nose, mouth, and eyes; full body
suits and hoods that supply clean air to a wearer; powered and
supplied air masks; self-contained breathing apparatus; and
essentially any other face masks.
[0059] The face mask of the present invention requires its wearer
to inhale with the nose and exhale with the mouth, such that the
two breathing activities take place in two separated chambers and
the discomfort associated with wearing face masks is minimized.
However, the wearer has the choice of breathing using his/her nose
only, as using a conventional face mask, with less comfort.
[0060] Reference is made to FIGS. 1 and 2, which illustrate an
embodiment of the present invention, a full-face face mask 100
covering the nose, mouth, and eyes of a wearer. FIG. 1 illustrates
a front view of face mask 100 and FIG. 2 illustrates a
cross-sectional view of face mask 100, taken along line A-A of FIG.
1. Face mask 700 comprises an outer face piece 102, an inner face
piece 104, a separation piece 106, an exhalation device 108, an
inhalation device 110, and a lens 112.
[0061] Face piece 102, which is designed to be conformal to the
face and is made of a semi-rigid but flexible silicone hybrid or
fluorosilicone material. Although other silicone and organic rubber
materials can be used (for example silicone rubber, EPDM, butyl
rubber, thermoplastic elastomer), the silicone hybrid and
fluorosilicone materials are preferred and have been selected
because of their flexibility. Other materials can be used for low
weight and low cost products, such as partially made of molded
plastic or polymer materials.
[0062] An in-turned (rolled periphery) flexible face seal 114 is
provided around the entire outer edge of face piece 102 and has an
integrally molded feature thereof. Seal 114 is intended to come
into contact with the face of the wearer, and is contoured to
conform to and form a leak-free seal with the wearer's face.
[0063] Inner face piece 104 is adapted to fit within face piece 102
and designed to be conformal to the face covering the nose and
mouth. Inner face piece 104 is, preferably, made of the same
material as face piece 102. Face piece 104 can be a separate part
installed inside face piece 102 or can be an integral portion of
face piece 102. Face piece 104 has a rolled flange seal 116,
disposed at the open portion thereof, sealing around the nose and
adjacent facial area of the wearer.
[0064] Separation piece 106 is provided for substantially dividing
inner face piece 104 into a nose portion 104a and a mouth portion
104b, thereby forming a nose chamber and a mouth chamber, such that
the gas communication between the two chambers is minimized and
such that inhalation air stream and exhalation air stream can be
separated to avoid inhalation, by the wearer, of the residual warm,
humid, and carbon dioxide rich exhaled air trapped inside the
interior gas space, whereby face mask 100 is comfortable and
hygienic to wear. Separation piece 106 can be a separate part
installed inside face piece 104 or an integral portion thereof. The
first end of separation piece 106 is attached on the inner surface
of face piece 104 and the second end thereof extends rearward
toward the wearer's facial area in between the nose and mouth,
across/around the cheek areas close to the mouth. Separation piece
106 is intended to come into contact with and is contoured to
conform to the wearer's face around the mouth and can have an open
feature or a closed feature encompassing the mouth.
[0065] Separation piece 106 is made of a substantially impermeable
and, preferably, semi-rigid material similar to those for face
pieces 102 and 104, and any other suitable materials known to those
skilled in the art and suggested by this invention disclosure.
[0066] Exhalation device 108 comprises a filter housing 118, filter
medium 120, and a filter cap 122.
[0067] Housing 118 is molded to face piece 102 so that material of
face piece 102 surrounds the edges of housing 118. There are open
slots on the front surface of housing 118 for permitting the wearer
to exhale. Filter medium 120 is disposed within housing 118. Filter
medium 120 includes an activated carbon filter 120a and a
particulate filter 120b. Filter 120b, preferably, comprises two
layers sandwiching filter 120a. Filter cap 122 is provided for
holding filter medium 120 in position. There is a central aperture
on filter cap 122 for allowing the wearer to exhale
therethrough.
[0068] Filter 120a is, preferably, made from a moldable carbon bed.
Typically, filter 120a is made by bonding activated carbon granules
using a thermoplastic binder material, such as polyurethane,
thereby immobilizing the carbon granules in the bed. The bonding
ratio (typically 5-15% polymer to carbon granules) is optimized for
both ruggedness and vapor absorption performance.
[0069] On the other hand, particulate filter 120b is typically made
from a thermally molded fibrous material or an electrostatic
material for more advanced applications. Particulate filter 120b
generally includes a shell layer for moisture protection.
[0070] FIG. 3 illustrates an alternative design of exhalation
device 108. In this design filter medium 120 is replaced with a
valve 124, as is widely used in many non-medical applications.
Valve 124 permits exhaled air to pass therethrough but will close
up during inhalation. Valve 124 includes a valve body 124a, which
has openings thereon allowing exhaled air to pass therethrough, and
a diaphragm member 124b, which is in a closed position closing up
the openings on valve body 124a. During exhalation, the increased
pressure inside the mouth chamber will deform diaphragm member 124b
outboard, such that valve 124 is in an open position. A tapered
portion is integral with diaphragm member 124b and snaps into a
suitable aperture in valve body 124a, whereby, diaphragm member
124b can be removed or replaced if desired.
[0071] Exhalation device 108 can be further alternatively designed
(not shown) such that it includes both filter 120 and valve 124, as
known in prior arts, whereby face mask 100 can protect other
persons or things from being exposed to contaminants expelled by
the wearer, as compared with the valve-only design. This design can
have medical, clean room, and many other applications.
[0072] FIG. 4 illustrates a cross-sectional view of inhalation
device 110, taken along line B-B of FIG. 1. Inhalation device 110
comprises a filter housing 126, filter medium 128, a filter cap
140, and a valve 142.
[0073] Housing 126 is molded to face piece 102 so that material of
face piece 102 surrounds the edges of housing 126. There are open
slots on the front surface of housing 126 for permitting the wearer
to inhale. Filter medium 128 is disposed within housing 126. Filter
medium 128 includes an activated carbon filter 128a and a
particulate filter 128b. Filters 128a and 128b possess the same
characteristics as filters 120a and 120b, respectively, of FIG. 2.
Filter cap 140 is provided for holding filter medium 128 in
position. There is a central aperture on filter cap 140 for
allowing the wearer to inhale therethrough. Valve 142 is provided
for permitting filtered air to pass therethrough but will close up
during exhalation, such that no exhalation air passes
therethrough.
[0074] There are apertures (not shown) on inner face piece 104
inline with inhalation device 110 for permitting filtered air to
pass therethrough to the wearer's nose. A plurality of air conduits
(not shown) can be provided in between face pieces 102 and 104 for
directing filtered air passing therethrough to the vicinity of eye
lens 112 first before going into inner face piece 104 for defogging
lens 112.
[0075] Reference is made to FIG. 1, again. Single-piece eye lens
112, which is semi-flexible and conforms to the facial structure of
the wearer, is molded or integrally bonded directly into face piece
102 using a silicone adhesive. Lens 112 is made of a polycarbonate
or a polyurethane material, and coated with silicate, acrylic, or
polyurethane formulations to provide scratch resistance. Lens 112
is designed with a polynomial curvature for optimum eye relief (25
millimeter) and visibility while having ample space for an optical
correction spectacle (not shown).
[0076] Face piece 102 is attached to a crown portion 144 via a
plurality of suspension flanges, generally designated as 146, and a
suspension device (not shown). A pair of elastic straps 148, which
are made from any material of sufficient elasticity, are connected
to opposite sides at the rear of crown portion 144 as by stitching.
Straps 138 are adjustably connected as by stitching to buckles 140,
which are connected to tabs 142 molded to face piece 102.
[0077] Face mask 100 requires its wearer to inhale with the nose
and exhale with the mouth. However, the wearer has the choice of
exhaling with the nose, as using a conventional face mask. In this
case, a one-way valve (not shown) can be provided in between the
nose chamber and the mouth chamber for permitting the exhaled air
to pass therethrough from the nose chamber to the mouth chamber and
then to pass through exhalation device 108 to an exterior gas
space.
[0078] Reference is, now, made to FIGS. 5 and 6, which illustrate
another embodiment of the present invention, a half-face face mask
150 covering the nose and mouth of a wearer. FIG. 5 illustrates a
front view of face mask 150 and FIG. 6 illustrates a
cross-sectional view of face mask 150, taken along line A-A of FIG.
5. Face mask 150 comprises a face piece 152, a separation piece
154, an exhalation device 156, and an inhalation device 158.
[0079] Face piece 152, which is designed to be conformal to the
face and is made of a semi-rigid but flexible silicone hybrid or
fluorosilicone material. Although other silicone and organic rubber
materials can be used (for example silicone rubber, EPDM, butyl
rubber, thermoplastic elastomer), the silicone hybrid and
fluorosilicone materials are preferred and have been selected
because of their flexibility. Other materials can be used for low
weight and low cost products, such as partially made of molded
plastic or polymer materials.
[0080] An in-turned (rolled periphery) flexible face seal 160 is
provided around the entire outer edge of face piece 152 and has an
integrally molded feature thereof. Seal 160 is intended to come
into contact with the face of the wearer, and is contoured to
conform to and form a leak-free seal with the wearer's face.
[0081] Separation piece 154 is provided for substantially dividing
face piece 152 into a nose portion 152a and a mouth portion 152b,
thereby forming a nose chamber and a mouth chamber, such that the
gas communication between the two chambers is minimized and such
that inhalation air stream and exhalation air stream can be
separated to avoid inhalation, by the wearer, of residual warm,
humid, and carbon dioxide rich exhaled air trapped inside the
interior gas space, whereby face mask 150 is comfortable and
hygienic to wear. Separation piece 154 can be a separate part
installed inside face piece 152 or an integral portion thereof. The
first end of separation piece 154 is attached on the inner surface
of face piece 152 and the second end thereof extends rearward
toward the wearer's facial area in between the nose and mouth,
across/around the cheek areas close to the mouth. Separation piece
154 is intended to come into contact with and is contoured to
conform to the wearer's face around the mouth and can have an open
feature or a closed feature encompassing the mouth.
[0082] Separation piece 154 is made of a substantially impermeable
and, preferably, semi-rigid material similar to those for face
piece 152, and any other suitable materials known to those skilled
in the art and suggested by this invention disclosure.
[0083] Exhalation device 156 comprises a filter housing 162, filter
medium 164, and a filter cover 166.
[0084] Housing 162 is molded to face piece 152 so that material of
face piece 152 surrounds the edges of housing 162. There are open
slots on the front surface of housing 162 for permitting the wearer
to exhale. Filter medium 164 is disposed within housing 162. Filter
medium 164 includes an activated carbon filter 164a and a
particulate filter 164b. Filter 164b preferably comprises two
layers sandwiching filter 164a. Filter cap 166 is provided for
holding filter medium 164 in position. There is a central aperture
on filter cap 166 for allowing the wearer to exhale
therethrough.
[0085] Filter 164a is, preferably, made from a moldable carbon bed.
Typically, filter 164a is made by bonding activated carbon granules
using a thermoplastic binder material, such as polyurethane,
thereby immobilizing the carbon granules in the bed. The bonding
ratio (typically 5-15% polymer to carbon granules) is optimized for
both ruggedness and vapor absorption performance.
[0086] On the other hand, particulate filter 164b is typically made
from a thermally molded fibrous material or an electrostatic
material for more advanced applications. Particulate filter 164b
generally includes a shell layer for moisture protection.
[0087] FIG. 7 illustrates a cross-section view of an alternative
design of exhalation device 156. In this design filter medium 164
is replaced with a valve 168, as is widely used in many non-medical
applications. Valve 168 permits exhaled air to pass therethrough
but will close up during inhalation. Valve 168 includes a valve
body 168a, which has openings thereon for allowing exhaled air to
pass therethrough, and a diaphragm member 168b, which is in a
closed position closing up the openings on valve body 168a. During
exhalation, the increased pressure inside the mouth chamber will
deform diaphragm member 168b outboard, such that valve 168 is in an
open position. A tapered portion is integral with diaphragm member
168b and snaps into a suitable aperture in valve body 168a,
whereby, diaphragm member 168b can be removed or replaced if
desired.
[0088] Exhalation device 156 can be further alternatively designed
(not shown) such that it includes both filter 164 and valve 168, as
known in prior arts, whereby face mask 150 can protect other
persons or things from being exposed to contaminants expelled by
the wearer, as compared with the valve-only design. This design can
have medical, clean room and many other applications.
[0089] Reference is made to FIG. 8, which illustrates a
cross-sectional view of inhalation device 158, taken along line B-B
of FIG. 5. Inhalation device 158 comprises a filter housing 110,
filter medium 112, a filter cap 114, and a valve 116.
[0090] Housing 110 is molded to face piece 152 so that material of
face piece 152 surrounds the edges of housing 110. There are open
slots on the front surface of housing 110 for permitting the wearer
to inhale. Filter medium 112 is disposed within housing 110. Filter
medium 112 includes an activated carbon filter 112a and a
particulate filter 112b. Filters 112a and 112b possess the same
characteristics as filters 120a and 120b, respectively, of FIG. 2.
Filter cap 114 is provided for holding filter medium 112 in
position. There is a central aperture on filter cap 114 for
allowing the wearer to inhale therethrough. Valve 116 is provided
for permitting filtered air to pass therethrough but will close up
during exhalation, such that no exhalation air passes
therethrough.
[0091] Reference is made to FIG. 5, again. A pair of elastic
straps, generally designated as 118, which are made from any
material of sufficient elasticity, are provided for holding face
mask 150 against the wearer's face.
[0092] Reference is made to FIGS. 9 and 10, which illustrate an
alternative embodiment of the present invention, a molded face mask
200 covering the wearer's nose and mouth. FIG. 9 illustrates a
front view of face mask 200. FIG. 10 illustrates a cross-sectional
view of face mask 200, taken along line A-A of FIG. 9.
[0093] Face mask 200 comprises a face piece 202, a separation
member 204, an elastic head band 206, and a nose clip 208.
[0094] Face piece 202 has a generally cup-shaped, face-fitting
configuration. The periphery of face piece 202 is shaped to contact
the face of the wearer over the bridge of the nose, across and
around the cheeks, and under the chin. Face piece 202 then forms an
enclosed space around the nose and mouth of the wearer.
[0095] Face piece 202 is made from a plurality of layers including
a thermally bonding fibers layer and some filtration layers.
Thermally bonding fibers bond to adjacent fibers after being heated
and cooled. These thermally bonding fibers form a generally
cup-shaped shape-retaining layer. A plurality of filtration layers
can be applied thereon. Face piece 202 is formed from a plurality
of layers of material selected to ensure that it has a degree of
flexibility to enable it to fit to the face of the wearer while
being stiff enough to retain its shape during use. An optional
corrugated pattern extends through all the layers of the central
region of face piece 202.
[0096] Separation member 204 substantially divides face piece 202
into a nose portion 202a and a mouth portion 202b, thereby forming
a nose chamber and a mouth chamber, such that the gas communication
between the two chambers is minimized and such that inhalation air
stream and exhalation air stream can be separated to avoid
inhalation, by the wearer, of the residual warm, humid, and carbon
dioxide rich exhaled air trapped inside the interior gas space,
whereby face mask 200 is comfortable and hygienic to wear. The
first end of separation member 204 is attached onto the inner
surface of face piece 202 and the second end thereof extends
rearward toward the wearer's facial area in between the nose and
mouth, across/around the cheek areas close to the mouth. The second
end of separation member 204 is intended to come into contact with
and is contoured to conform to the wearer's face.
[0097] Separation member 204 is made of a substantially impermeable
material, preferably, soft and moisture resistant, e.g., robbers,
semi-rigid but flexible silicone hybrid or fluorosilicone
materials, foams, papers coated with wax, molded fibers coated with
impermeable materials, etc., and any other materials known to those
skilled in the art and suggested by this invention disclosure.
[0098] FIG. 11 illustrates a perspective view of face mask 200,
viewing from the back indicating a design of separation member 204.
Separation member 204 extends substantially across face piece 202
laterally. The middle portion of separation member 204 has a dent
feature, which is conformal to the facial area in between the nose
and mouth.
[0099] FIG. 12 illustrates a perspective view of face mask 200,
viewing from the back, indicating an alternative design of
separation member 204. The upper portion of separation member 204
forms a semi-cylindrical shape extends substantially around the
facial area around the mouth and below the nose. The lower portion
thereof extends downward toward the lower edge of face piece 202.
The middle portion of separation member 204 has a dent feature,
which is conformal to the facial area in between the nose and
mouth.
[0100] Those skilled in the art will appreciate in view of this
invention disclosure, however, that other geometric shapes of
separation member 204 could be used for the purpose of
substantially dividing face piece 202 into nose portion 202a and
mouth portion 202b. For example, separation member 204 can have a
closed feature encompassing the mouth of the wearer.
[0101] Reference is made to FIG. 9, again. Elastic head band 206 is
stapled to face piece 202 at each side to hold face mask 200
against the face of the wearer.
[0102] Nose clip 208 is secured on the outer face of face piece
202., adjacent its upper edge, to enable face piece 202 to be
shaped in this region to fit to the wearer's nose bridge.
[0103] FIGS. 13 through 16 illustrate various methods of attaching
separation member 204 onto face piece 202. In FIG. 13, separation
member 204 is attached onto the inner surface of face piece 202. In
FIG. 14, nose portion 202a and mouth portion 202b are separate
parts joining together by separation member 204. In this case, nose
portion 202a and mouth portion 202b can be readily made of
different materials for optimal filtration material utilization. In
FIG. 115, which illustrates a similar design as that in FIG. 14,
separation member 204 has a protrusion protruding out of face piece
202 toward the exterior gas space. This protrusion is intended for
guiding exhaled air further away from the wearer's face for
minimizing the fogging of glasses worn by the wearer. In FIG. 16,
face piece 202 has multiple layers. Separation member 204 is
separating the inner layers and is covered by the outer layers.
[0104] Those skilled in the art will appreciate in view of this
invention disclosure that many other methods of attachment are
possible and are suggested. Separation member 204 is joined to face
piece 202 by such processes as molding, gluing, stitching and other
types of joining processes known to those skilled in the art and
suggested by this invention disclosure. For example, Separation
member 204 can be a detachable/removable part with the first end
thereof standing on face piece 202.
[0105] FIG. 17 illustrates an alternative design of face mask 200,
in which an exhalation device 209 is provided. Exhalation device
209 is installed on the outer surface of face piece 202. Exhalation
device 209 comprises a one-way valve for allowing exhaled air to be
purged from the interior gas space more easily. Exhalation device
209 can further includes a filtration material, as known in prior
arts, whereby face mask 200 can protect other persons or things
from being exposed to contaminants expelled by the wearer, as
compared with the valve-only design. This design can have medical,
clean room, and many other applications. Reference is directed to
previous discussion for detailed structures of the one-way valve
and filtration material.
[0106] Reference is made to FIGS. 18 through 20, which illustrate a
further more embodiment of the present invention, a fold flat face
mask 210. FIG. 18 illustrates a front view of face mask 210. FIG.
19 illustrates a perspective view of face mask 210 on a wearer.
FIG. 20 shows a cross-sectional view of face mask 20, taken along
line A-A of FIG. 18, as worn by a wearer.
[0107] Face mask 210 includes a face piece 212, a separation member
214, a plurality of fasteners 216, and a nose clip 218.
[0108] Face piece 212 has a plurality of folds, which enable face
piece 212 to extend outward over the contours of the wearer's face,
and is designed to cover the nose and mouth of the wearer. Face
piece 212 is made of one or multiple layers of air-permeable
filtration materials.
[0109] Separation member 214 substantially divides face piece 212
into a nose portion 212a and a mouth portion 212b, thereby, forming
a nose chamber and a mouth chamber, such that the gas communication
between the two chambers is minimized and such that inhalation air
stream and exhalation air stream can be separated to avoid
inhalation, by the wearer, of the residual warm, humid, and carbon
dioxide rich exhaled air trapped inside the interior gas space,
whereby face mask 210 is comfortable and hygienic to wear. The
first end of separation member 214 is attached onto face piece 212
and the second end thereof extends rearward toward the wearer's
facial area in between the nose and mouth, across/around the cheek
areas close to the mouth. The second end of separation member 214
is intended to come into contact with and is contoured to conform
to the wearer's face.
[0110] Separation member 214 is made of a substantially impermeable
material, preferably, soft and moisture resistant, e.g., robbers,
semi-rigid but flexible silicone hybrid or fluorosilicone
materials, foams, papers coated with wax, molded fibers coated with
impermeable materials, etc., and other materials known to those
skilled in the art and suggested by this invention disclosure.
[0111] FIGS. 21 and 22 illustrate perspective views of separation
member 214, viewing from the back, indicating two different designs
of separation member 214. The attachment of separation member 214
onto face piece 212 and other features are similar to those for
molded face mask 200 discussed previously. Therefore, reference is
directed to the discussion of face mask 200, in FIGS. 9 through 17
for detailed information.
[0112] One advantage worth mentioning about face mask 210 of the
present invention is that, properly designed, separation member 214
will help face piece 210 form a cup-shaped, face-fitting
configuration, such that face piece 212 does not come into direct
contact with the facial area around the nose and mouth. This
further improves the comfort level of wearing face mask 210,
compared with prior art products. In this case, face mask 210 is
functioning similar to molded face mask 200. Therefore, exhalation
valves (not shown) can be provided for facilitating the purging of
exhaled air. Reference is directed to the discussion of face mask
200 in FIGS. 9 through 17 for detailed information.
[0113] Reference is made to FIGS. 18 and 19, again. Fasteners 216
are provided to secure face mask 210 over the face of the wearer.
In the illustrated embodiment, fasteners 216 include an upper pair
of tie straps 216a and a lower pair of tie straps 216b that extend
from top edge and bottom edge of mask 210, respectively. When mask
210 is worn, tie straps 216a and 216b are secured around the head
and the neck of the wearer.
[0114] Nose clip 218 is secured on the outer face of face piece
212, adjacent its upper edge, to enable face piece 212 to be shaped
in this region to fit to the wearer's nose bridge.
[0115] In the case of a face mask in which the filtration material
is made of multi-layers of meshed fabrics, reference is made to the
discussion of fold flat face mask 210 described previously, in
FIGS. 18 through 22 for detailed information.
[0116] In operation, a method of using the face mask of the present
invention comprising the steps of:
[0117] 1) providing a face mask comprising a face piece for
covering at least the nose and mouth of a wearer, and a separation
member, made of a substantially impermeable material, substantially
dividing the face piece into a nose portion and a mouth portion,
thereby forming a nose chamber and a mouth chamber, such that the
gas communication between the nose chamber and the mouth chamber is
minimized, having a first end attached onto the face piece and a
second end extending rearward toward the facial area in between the
nose and mouth of the wearer and the cheek areas around the mouth,
such that the second end of the separation member is conformal to
the wearer's face around the mouth;
[0118] 2) fastening the face mask onto the wearer's face, such that
the nose portion is covering the nose area and the mouth portion is
covering the mouth area, and such that the separation member is
disposed in between the nose and mouth of the wearer;
[0119] 3) inhaling with the nose; and
[0120] 4) exhaling with the mouth; and
[0121] whereby the exhaled air is directed out of the interior gas
space through mouth portion and the re-inhalation of residual
exhaled air is totally eliminated and the fogging of eyeglasses is
substantially minimized.
[0122] Accordingly, readers will see that this face mask of the
present invention can be used for various applications. This face
mask has a separation member, made of a substantially impermeable
material, substantially dividing the face piece into a nose portion
and a mouth portion, thereby forming a nose chamber and a mouth
chamber, such that the gas communication between the two chambers
is minimized and such that inhalation air stream and exhalation air
stream can be separated to avoid inhalation, by the wearer, of the
residual warm, humid, and carbon dioxide rich exhaled air trapped
inside the interior gas space and within the filtration materials,
whereby the face mask is comfortable and hygienic to wear. This
face mask is beneficial to the people who wear glasses, as well,
because the fogging of glasses is minimized due to directing the
exhaled humid air downward through the mouth chamber. This face
mask of the present invention is especially beneficial to those who
have to wear a face mask for a pro-longed period of time, such as
clean-room workers, operation-room doctors and nurses, patients
suffering from extremely contagious respiratory diseases, like
SARS, firefighters in fighting fire disasters, soldiers in chemical
and biological battle fields, etc.
[0123] The present invention has been described in an illustrative
manner. It is to be understood that the terminology, which has been
used, is intended to be in the nature of words of description
rather than of limitation.
[0124] Although the invention has been described in its preferred
forms and structures with a certain degree of particularity, these
should not be construed as limiting the scope of the invention but
as merely providing illustrations of some of the presently
preferred embodiments of this invention.
[0125] Thus it is understood that the present disclosure of the
preferred forms can be changed in the details of construction and
in the combination and arrangement of parts without departing from
the spirit and the scope of the invention as hereinafter
claimed.
* * * * *